CAPE-VERDE GROUP. 491 



is likewise traceable in the presence at the Cape-Verdes of the 

 minute Patula pusilla, Lowe (so common at the Madeiras, 

 and which exists also at the Canaries and the Azores), as well 

 as in the close affinity of the Pupa molecula, Dohrn, and 

 Dohrni, Pfeiff., with the Madeiran subfossil P. linearis, and with 

 the ' var. anconostoma ' of the European P. umbilicata, Drap., 

 which is so universal throughout the more northern Groups. 

 Moreover the subfossilized H. primaiva, from Sal, is compared 

 by Morelet to Lowe's H. undata, of Madeira. 



It is to be noted also that the group Leptaxis, which is so 

 largely developed in the Madeiran and Cape- Verde archipelagos, 

 and even at the Azores, does not possess so much as an exponent 

 at the Canaries ; for although it has occasionally been cited for 

 certain Canarian species (as, for instance, by Mousson, for the 

 subfossil H. digna from Oromera, and for the H. Berkeleyi from 

 Grand Canary), the latter do not in reality fall under Leptaxis 

 at all as originally defined by Mr. Lowe, — the H. chrysomela, 

 membranacea, furva, and erubescens, which are essentially 

 Madeiran, being the sole types, apart from these Cape-Verdian 

 ones (and eight from the Azores), of that particular section. 

 And as regards the Canarian fauna, there seems to be no 

 special point in which it touches that of the Cape-Verdes, — 

 such forms as the Helix lenticula, Bulimus ventricosus, and 

 Stenogyra decollata having already been shewn to be of doubt- 

 ful import in the general questions of geographical distribution. 

 Still the diminutive Patula pusilla, Lowe, occurs in both 

 Groups ; and it is just possible that the subfossil Pupa macro- 

 gyra, of Mousson, from Gromera, may be found to make some 

 slight approach, as regards affinity, to the Stenogyra subdia- 

 phana, King, which is so characteristic of the Cape-Verdes ; 

 but, as I have had no opportunity of inspecting the tyDe, this is 

 merely a conjecture. Also the Patula Bertholdiana, Pfr., has 

 manifestly a good deal in common with my P. garachicoensis 

 from Teneriffe, though not sufficiently so perhaps to be of much 

 significance. 



The presence in the Cape Verdes of the widely spread genus 

 Succinea, which is so strongly expressed at St. Helena, but 

 which has no representative in the more northern archipelagos, 

 is geographically interesting ; and the existence of Melania, 

 which possesses so extensive a range in the littoral districts of 

 the African continent but which does not make its appearance 

 in any of the other islands, should be particularly noticed. 



In the systematic catalogue at the close of the present 

 Section I have (as in the corresponding ones pertaining to the 

 other Groups) placed an asterisk (*) against those few species 

 which have been met with also in a subfossil state : and in 



